i) The rational number that does not have a reciprocal `-> 0` as `1/0 = 00`<br>
ii) The rational numbers that are equal to their reciprocal `->1,-1` as `1/1 = 1 and 1/-1 = -1`<br>
iii) The rational number that is equal to its negative `-> 0` as `-0 = 0`.<br>